1. Field of the Invention
The present invention relates to electro-hydraulic conversion systems, and more particularly to providing hydraulic power to waste compaction systems.
2. Description of the Prior Art
Hydraulic compactors are frequently used in the collection and disposal of waste. The classic example of such a hydraulic waste compactor is a waste removal truck such as is found in U.S. Pat. No. 3,941,263 to Clucker et al., entitled "Method for Controlling the Packer Blade of a Refuse Truck." Such trucks typically use the truck engine as the source of power to drive the hydraulics of the waste compactor. Other prior art devices of this type are demonstrated by U.S. Pat. No. 3,802,585 to Churchman, entitled "Compactor for Refuse or Other Compressible Material," and U.S. Pat. No. 5,015,144 to Smith et al., entitled "Apparatus for Loading Material Into a Storage Compartment and Associated Fluid Pressure Delivery System." Again, these systems utilize the truck as the source of power for the hydraulics, and the container for holding waste is not separable from the truck.
Another apparatus frequently used in removal of waste is onsite waste containers. The waste containers are either periodically emptied by the prior art trucks as discussed above, or are removed as a unit, and taken to the waste disposal site. The problem with these prior art systems is that each suffers from the frequency with which the trucks must tend to the waste container. The sheer volume of waste which has not been compacted can result in requiring the disposal truck to frequently visit the site where the trash container is located, or the requirement of numerous containers. Either alternative is costly.
Compacting-type waste disposal dumpsters are becoming increasingly popular in waste management because such compacting dumpsters can compact waste into a smaller volume prior to pick-up and disposal. As shown in FIG. 1, prior art units or "compactor containers" typically include a large storage bin or container 8, a hopper 9 generally mounted at one end of the container, and a hydraulically-actuated compactor 11. The compactor 11 powers a compressing ram 14 that compresses waste placed into the hopper 9 and forces the compacted waste into the container 8.
In most applications, power for the hydraulic compactor 11 is provided from a source associated with a building or other permanent facility, such as a power unit 13 comprising a 220 VAC-powered hydraulic compressor. Hydraulic hoses with quick connect/disconnect fittings 12 are used to connect pressurized hydraulic fluid to the compactor 11. When the bin 8 is full, the compactor 11 is disconnected from the hydraulic source and the whole container 8 including hopper 9 and compactor 11 is transported by truck to a waste disposal site. In an alternate method, the container is disconnected from the compactor and then transported.
One particular impediment to the use of such waste compactor containers is the difficulty of obtaining power. Many facilities needing waste compaction do not have 220 VAC; alternative power sources may not be readily available. Typical examples include construction sites, rural county dumpster sites and recycling sites.
It is known in the prior art to provide for portable sources of hydraulic power, such as that shown in U.S Pat. No. 4,211,080 to White, entitled "Hydraulic Power Packs." White discloses a gasoline portable hydraulic unit. Having the actual power source on the portable unit, in addition to the apparatus for converting the power from the power source to hydraulic power results in a large, cumbersome portable unit. A system such as demonstrated by White also requires the user to provide hydraulic hoses for connection to the tools.
The preferred embodiment of White demonstrates the use of a petrol engine power source. Such a power source suffers from the large number of mechanical parts, which frequently results in costly breakdowns, and therefore requires regular maintenance and service including tune-ups, replacement of worn parts, replacement of fuels and lubricants.
If a gasoline engine is used for the purpose of trash compaction, a very large engine, like that of the White reference, would be necessary to provide the torque necessary for proper operation. Because of the gasoline used in the engine, the unit could not be permanently attached to the side of a compactor system because when the system was tilted, the gas and oil would leak out of the apparatus during emptying of the container. A gas engine system would also not hold well in the harsh environment associated with waste products, including dust and weather.